Locking check arm



' 9 I c. w. VAN RANST 2,225,725

LOCKING crmcx ARM Filed May 12, 1936 2 Sheets-Sheet 1 k INVENTOR. fi'amekzzs If)? Farsi ATTORNEY5.

c w. VAN RANST 2225;725

LOCKING CHECK ARM I Filed May 12, 1936 2 Sh6etS-Sh9et 2 J26, (ma M ATTORNEYS,

Patented Dec. 24, 1940 UNITED STATES PATENT OFFICE Application May 12,

8 Claims.

This invention relates to checks arms and more particularly to check arms .of the so-called self locking type which may be used in connection with structures having hinged covers, such, for instance, as the rear compartments of motor Vehicle bodies, cabinet tops, trunk tops and .thelike.

One of the principal objects of the present invention is to provide a self-locking check armfor use withhinged covers which effects a secure and dependable locking of the cover in its open position, and which is adapted to hold the cover in the locked position until it is desired to .close the same, in which case the unlocking ,is simply and easily effected by the automatic operation of the checkarm.

Another object of the invention is 'to provide a device of the above character in which locking and unlocking .can be effected, when desired, solely by the movements of the cover without the necessity of performing manual operations on the locking mechanism or the check arm, thus preventing possible injury to the hands or fingers of the operator.

Another object of the inventionis to provide a self-locking check arm in which the locking and unlocking ,results from similar regular movements of the cover at the end of its upper movement to raised position.

A still further object of the invention is to provide a self-locking check arm which can be used selectively as a locking check arm, or as a non-locking check arm.

It is a still further object .of the present invention to provide a self-locking check arm which is economical to manufacture and which consists of comparatively few parts of sturdy construction, and which is compact ,in design and positive in its operation.

Other objects and advantages of this invention will appear in the following description and appended claims, reference .beinghad to the accompanying drawings forming apart of this specification, wherein one embodiment of the present invention is illustrated.

In the drawings, wherein like reference characters refer to like parts throughout the several VleWS,

Fig. l is a side view of a hinged cover provided with a self-locking check arm of my invention, solid lines indicating positions of the arm and the cover in fully extendedposition thereof, While the dotted lines indicate the extent of the locking and of the unlocking movements;

Fig. 2 is aperspective view-of the lockingmech- 1936, Serial No. 79,331

anism, expanded to show the separate parts more clearly;

Fig. 3 is a perspective view of the locking mechanism showing the relative positions of its parts as the cover is m an intermediate position in its opening stroke;

Fig. 4 is a View similar to Fig. 3 showing the relativeposition of the parts of the locking mechanism when the cover has reached the end of its opening stroke; 10

Fig. 5 is a view similar to Fig. 4 showing the relative position of the parts of the locking mechanism when the cover is raised to the position for looking the arm;

Fig. 6 is a view which is similar in part to that of Fig. 5 showing the locking mechanism in its fully locked position; i

Fig. '7 shows the relative position of the parts of the locking mechanism when the cover is raised for unlocking the arm; {20

Fig. 8 is a perspective view illustrating the relative position of the parts of the locking mechanism when the same is unlocked by the downward movement of the cover.

Before explaining in detail the present inven- 325 tion, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in Various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention claimed herein beyond the requirements of the prior art.

In the drawings there is illustrated, by way of example, a self-locking check arm embodying my invention, which comprises a dead link [0 and a live link H, which links are hinged together as at I3, one end of the structure so formed being hinged to the fixed structure, such as indicated by .A, at a point such as l2, while the other end has a rigid connection with thecover, such as .C, hinged to the structure A as at h. In this form the structure represents a cover provided with a simple check arm and the entire structure constitutes what is known in the art as a four-member linkage, the structure A representing the fourth member.

In addition to the above, the check arm of my invention is provided with a self-locking mechanism operatively secured to the live link l:-|,:and in assembled condition rigidly afiixed to the cover C. The function of said mechanism is to lock automatically the cover C in its open position. In my novel self-locking check arm the locking mechanism is of such a character that it -locks and unlocks the cover during its regular movement. The locking and unlocking of the check arm are accomplished by identical movements of the cover, that is, by an upward movement followed by a downward movement of the cover upon its release. As a result of such construction, it is possible to swing the cover provided with my novel check arm to the very end of its opening stroke without locking the same, and then effecting the automatic locking of the cover in such raised position. This arrangement is particularly convenient when. opening .is .done with but one hand of the operator. The cover,

therefore, may be swung wide open, an article taken from within a compartment closed by the cover, and the cover may then be let down without an unnecessary and annoying locking action taking place. If, on the other hand, the article desired is not easily obtainable or cannot be found at once, the cover may be locked in the open position by moving it up and letting it down under its own weight. This movement will fully lock the cover, and both hands of the operator will become available for use. Having obtained the article needed, or finished the work in the compartment of the structure A, the cover C is unlocked automatically in the usual process of closing the cover and without the operator using his hands for any other manipulations than are necessary for closing the cover. All that is necessary for unlocking the cover is to move it again upwardly, and to let it go down under its own weight.

Referring more particularly to Fig. 2, the l0cking mechanism comprises a plate 2|) adapted to be secured to the cover C by any suitable means, such as a bent portion 2| provided with screw holes 22 and 23 adapted to receive suitable screws or bolts. The plate 20 is provided with a circular slot 25 having the approximate geometric center of its curvature located adjacent the center of the hole 24. The circumferential extent of said slot 25 may vary in accordance with the stroke requirements of the cover C, 120 circular degrees being one of the suitable angles for average cases. At both ends of said circular slot 25 there are provided short radial slots 25 and 21, the slot 25 being somewhat longer than the slot 21. All of said slots have substantially equal Width. The location of the slot 21 is such that a radial line passed from the center of the hole 24 and the center line of the slot 21 is substantially parallel to the edge of the plate along the bent portion 2|, thus insuring complete closing of the cover C.

The internal angles at the junctions of the slot 25 with the slots 26 and 21 are rounded,

such as at 28, to provide for smoother operation of the device. The hole 24 receives a flat-headed pin l6 riveted to the plate 20 in the said hole 24 and adapted to slide in a longitudinal slot l5 provided in the live link The length of the slot I5 is substantially equal to that of the radial slot 26. The flat head I! of the pivot I5 operates to hold the link II to the plate 20. A similar function is performed by the head 33 of a camheaded rivet 35 riveted to the link H as at M, and adapted to slide in the slots 25, 26 and 21. The distance between the centers of the pin l5 and the rivet 35 is substantially equal to the radial distance between the center of the pin l6 and the center line of the slot 25. When the cam-headed rivet 35 is in the slot 25, the cylindrical portion 39 is maintained in the slot 25, but no other movement except rotation of the plate 23 around the pin I6 is permitted, sliding movement of said pin I5 in the slot 5 being prevented by engagement of the cam-headed rivet 35 with a side of the slot 25. Upon entering the area 29 which is common to both slot 25 and slot 26, the rivet 35 is no longer restricted by the slot 25 and it may be moved away from the pin I6 into the extremity of the slot 25. The

length of the slot I5 is substantially equal to that of the slot 25, and thus as the cam-headed rivet 35 reaches the outward extremity of said slot 25, the pivot l5 reaches the extremity of the slot l5 at a point remote from said rivet 35. The rivet 35 comprises a cylindrical head 38, a cylindrical slot-engaging portion 39, and a prismatic portion 35. The top surface of the head 38 is provided with a cam surface 31, which extends at an angle to a plane perpendicular to the center line of the rivet which is less than approximately 90 degrees and preferably about 30 degrees. The traces of the plane of said portion 31 are substantially perpendicular to the center line of the ,link H and, consequently, are parallel to a tangent drawn at the respective points where the rivet 35 engages the slot 25. This feature is particularly apparent in Fig. 3. Since this positionof the portion 31 is important to the proper operation of the mechanisms, the portion 36 is made prismatic and is riveted into a hole of corresponding shape, such as the hole M, in order to insure said position even in cases where said rivet may become loose in the hole l4.

The plate 20 is provided with a locking tooth 32 which is formed preferably integrally with said plate. Said tooth 32 has a straight locking face 33, and a slanted face 34, as shown in Figs. 2 and 5.

Between said locking tooth 32 and the slot 25 there is provided a hole 30 receiving a pivot 50, which pivot is adapted to be riveted in said hole at its end portion 5|. Said pivot comprises a body portion 52, and a head 53. A star or rotating member, designated generally by the numeral 45, is mounted on said pivot and is held in yielding contact with the plate 20 by a spring 55 arranged on said body portion 52 and retained in compression by the head 53. The star member 4|] comprises a body part 4| provided with a centrally located hole 42, said hole being adapted to receive the body portion 52 of the pivot member 5!]. On the surface of said body part 4| and circumferentially arranged around said hole 42, there is provided a plurality of substantially equally spaced teeth 43. Each of said teeth 43 includes a straight face 44, and an oblique face 45. The circumferential edge of said body part 4| is provided with a plurality of lugs 45 extending substantially perpendicular to the surface of said body part 4|. The number of said lugs is onehalf of the number of the teeth 43. I prefer to form both the lugs 46 and the teeth 43 integrally with said body part 4|, and to have ten teeth such as 43, and five lugs such as 46. The spaces 41 between the two adjacent lugs are such that the cam-headed rivet 35 can freely pass" through any of them. The star member 40 is adapted to rotate in one direction only, and in the present embodiment said rotation is in the clockwise direction. Rotation in the opposite direction is prevented by the locking tooth 32, and also by the cam-headed rivet 35 when the same is in the space 29. When rotated in the clockwise direction, the star member 40 climbs the inclined face of the lockingtooth 32, which is engaged by the oblique face of a respective tooth 43 and goes over said tooth, the spring 55 being compressed by said action of the member 40 to permit said member going over said locking tooth. It is apparent that when the member 40 is attempted to be rotated in the counterclockwise direction, the straight face of said locking tooth 32 is engaged by the straight face of a respective tooth 43 and such climbing over is impossible.

In operation, when the cover C is being swung to the open position, the cam-headed rivet 35 slides in the groove 25 as shown in Fig. 3. When said cam-headed rivet reaches the space 23, as shown in Fig. 4, the cover C is at the end of its opening stroke. As has been mentioned previously, no locking results from the position of the rivet 35 at the end of the slot 25. For locking the cover in the open position, the same is moved upwardly, in consequence whereof the cam-headed rivet 45 moves down to the end of the slot 26. In the course of said movement, the rivet 35 engages by its cylindrical head 35 the straight face 44 of a tooth 43 and pressing upon said face, turns the star member 4!] onetenth of turn, thus bringing a respective lug 46 in a position where said lug crosses 0r bridges the slot 25, as shown in Fig. 5, and locks the camheaded rivet 35 in the slot 25.

For a fuller understanding of the operation of my device, it is essential to note that Figs. 5, 6, 7 and 8 illustrate the relative position of the parts with reference to the moment when the described movement ends, while the arrows put on the plate and on the star member indicate the direction of the relative movement of said plate and said star member with respect to the link H, which has brought the parts into their respective positions shown in the figures.

When the cover C is released and drops down under its own weight from the position shown in Fig. 5, the rivet 35 comes into the position shown in Fig. 6. It Will be appreciated that in this condition the rivet 35 is locked in said position, since it cannot move along the slot 25 on account of said slot 25 being closed by the lug 46, downward movement of said rivet 35 along the slot 26 being prevented by the weight of the cover holding the plate in such a position that the rivet 35 cannot move out of'the slot 26. Self-unlocking of the mechanism being thus prevented, the cover C is securely locked in its open position.

For unlocking the cover C, the same is again moved. upward, which movement operates to bring the rivet 35 into the position shown in Fig. 7. In the course of said movements, the rivet 35 engages the next tooth 43 and moves the star member 40 one-tenth of a turn in the clockwise direction, thus setting the cut-out portion 4! thereof across the slot 25, and thus opening the same for the passage of the rivet 35 through the slot 25. When the cover C is thus released, the slot is ready to be moved relative to the rivet until the cover is in the closed position. Such condition is illustrated in Fig. 8.

It will now be understood in View of the foregoing, that at each movement of the slot 26 relative to the rivet 35 the star member is moved clockwise one-tenth of a turn when it contacts with the rivet 35 at th end of the movement. Counter-clockwise rotation of the member 40 is prevented at all times by the locking tooth 32. It should be particularly notedthat said movement of the slot relative to the rivet 35 operates alternatively to lock and to unlock the locking mechanism due to its action on the member 40.

Should it be desirable to set my locking check arm for operation as a simple non-locking check arm, the same may be done by moving the slot 2.5-re'lative to the rivet 35, such as shown in Fig. 3, and then manually turning said member 40 in a clockwise direction one-tenth of a revolution. This will bring one of the lugs 46' across the slot 25. 'In this condition the lug 46 will serve as a stop for the rivet 35 at the end of the opening stroke of the cover C, and will prevent operation of the locking mechanism.

It is to be understood that the rotating member 40 may be placed at various positions relative to the check arm, that is, it may be placed on the body proper, at the joint of the check arms, or on the cover, as here shown only by way of example. Also, the link members may be of various forms, and the slot with which the rotating member is associated may be formed in a fixed member secured to the body proper or in the check arm. All such arrangements are within the purview of this invention and are included within the scope of the appended claims.

Thus, in one of its broader aspects, my invention contemplates providing a novel locking check arm for use in connection with hinged covers, operating to lock and unlock a hinged cover in the course of its regular movement when being opened or closed.

-I claim:

1. A check device for a swinging lid or the like comprising a pair of bars pivotally connected together at adjacent ends, the outer ends thereof being adapted to be pivoted respectively to a support and to said lid, locking mechanism between one of the bars and said lid for maintaining the lid in raised position, said mechanism including a rotatable latch member and a keeper carried one by the lid and the other by the upper bar, spring means for urging the latch member into latching position and means actuated by raising the lid for'releasing said latch member. 2. A self-locking check arm comprising two hinged links and a locking mechanism, said looking mechanism including a plate having a path cam slot therein and adapted to be secured to a hinged cover, a pin secured to one of said links and movable in said slot, and a rotating member having a plurality of open and closed sections rotatably secured to said plate and overlying a portion of said path cam slot, and means for rotating said rotating member actuated by an upward movement of the cover at the end of the swinging movement of the opening stroke thereof followed by a slight downward movement thereof, whereby a closed section of said rotating member is moved across a portion of said path cam slot and locks saidpin therein, said means effecting rotation of said rotating member upon a succeeding identical movement of said cover whereby said closed section is moved away from said slot and an open section of said member is moved into position relative to said slot to permit movement of said pin throughout all of said path cam slot.

3. A self-locking check arm comprising hinged links and a locking mechanism, said locking mechanism including a plate adapted to be secured to a hinged cover, a path cam slot formed in said plate, a stud secured to one of said hinged links and movable in said cam, and a rotating member rotatably secured to said plateandhaving a turned peripheral edge portion formed with a plurality of open and closed sections arranged to register with said cam slot and to permit or restrain movement of said stud therein, means carried by said stud for rotating said rotating member in one direction through a predetermined fraction of a turn as said cover is moved upwardly to the end of its permitted swinging movement to bring said open and closed sections in alignment with said cam slot and thereby to lock and to unlock said mechanism by restraining or permitting movement of said stud in said cam slot,

4. A self-locking check arm including a check arm andlocking mechanism comprising a plate adapted to be secured to a cover and provided with a circular slot substantially coincident with the angle through which said cover may be opened and a radial slot communicating with said circular slot; a pin movable in said slot and carried by said check arm; a star-shaped member rotatably secured to said plate adjacent said radial slot and having a peripheral rim having successive open. and closed portions overlying said radial slot adjacent its connection with said circular slot, means carried by said pin and operable on said star-shaped member to effect rotation thereof a predetermined fraction of a revolution upon movement of said pin into said radial slot in response to an upward movement of said cover at the end of the swinging opening movement thereof, said rotating movement of said star-shaped member operating successively to bring the open or closed portions of the peripheral rim into position adjacent the point of connection between said circular slot and said radial slot and thus topermit or restrain movement of said pin in said radial slot synchronously with swinging movement of said cover when in'its open position.

5. A self-locking check arm comprising a dead link adapted to be hinged by one of its extremities to a fixed structure; a live link hinged by one of its extremities tothe free end of said dead link and at its other extremity pivotally connected with a plate adapted to be secured to a cover hinged tosaid structure, said plate having a circular slot and a radial slot at the end of said circular slot and forming a path cam therein; a rivet carried by said live link and movable in said path cam; a rotating member provided with a plurality of lugs adapted to prevent movement of said rivet into said circular slot from said radial slot, and a plurality of openings adjacent said lugs and adapted to permit movement of said rivet throughout the entire path cam, said rotating member being rotatably afiixed to said plate adjacent an end of said path cam with said lugs overlying said path cam, means for effecting rotation of said rotating member through a predetermined fraction of a revolution comprising a cam head carried by said rivet and adapted to move said rotating member upon movement of said rivet in said radial slot, the rotative movement of the said rotating member operating successively to move said lugs away from said path cam and thereby to permit movement of said rivet in said circular and radial slot and to move said lugs across said path cam to limit movement of said rivet in said radial slot and thereby to unlock and lock said check arm at the end of the opening movement of said cover.

6. A self-locking check arm comprising a dead link adapted to be hinged to a fixed structure at one of its extremities; a live link hinged to said dead link at one of its extremities, its other extremity being provided with a short longi tudinal slot and a rivet having a cam head and a shank secured thereto adjacent said slot and intermediate the extremities of said live link; a plate adapted to be secured to a cover hingedly secured to the fixed structure, a pin on said plate engaging the longitudinal slot of said live link and securing said live link to said plate for pivotal and sliding movement relative thereto, said plate having a circular slot terminating in a communicating relatively short radial slot, said slots being located and arranged to receive the shank of said rivet and permit movement of the said shank therein; a rotating member mounted on said plate adjacent said radial slot and having a portion engaged by the cam head of said rivet, said rotating member having a plurality of spaced lugs overlying said radial slot and adapted to separate said circular slot from said radial slot upon rotation of said member through a predetermined fraction of a revolution when said rivet is moved in said radial slot in response to movement of said cover at the end of its opening stroke.

7. A device of the class described comprising a first member and a second member pivotally connected together, a ratchet-wheel rotatively mounted on said first member, a detent means fixedly secured for rotation with said ratchetwheel, said second member having a portion which strike's'against the detent means or passes thereby, depending upon the rotative position of said detent means, and means on said second member engaging said ratchet-wheel to rotate said ratchet-wheel upon relative pivotal movement of said first and second members to thereby rotate said dete-nt means alternately to its stopping and clear positions.

8. A device of the class described comprising a first member and a second member pivotally connected together, said first member having an outwardly directed arm portion, a ratchet-Wheel rotatively mounted on said arm portion, a detent means fixedly secured for rotation with said ratchet-wheel, said second member having a portion which strikes against the detent means or passes thereby depending upon the rotative position of said detent means, and means on said second member engaging said ratchet-wheel to move said ratchet-wheel upon relative pivotal movement of said first and second members to thereby rotate said detent means alternately to its stopping and clear positions.

CORNELIUS W. VAN RANST. 

